CNN — Certified Nephrology Nurse Exam
2026–2027 | Comprehensive 100-Question
Practice Test with Answers & Rationales| Pdf
Access Already Graded A+.
Section 1: Renal Anatomy, Physiology & Assessment
1. What is the primary functional unit of the kidney?
A. Nephron
B. Alveolus
C. Hepatocyte
D. Neuron
Answer: A
Rationale: The nephron is the functional unit of the kidney and performs filtration,
reabsorption, and secretion.
2. Which structure is primarily responsible for initial filtration of blood in the nephron?
A. Loop of Henle
B. Glomerulus
C. Collecting duct
D. Distal tubule
Answer: B
Rationale: Blood is initially filtered through the glomerular capillaries into Bowman's capsule.
3. Which hormone increases water reabsorption in the kidney?
A. Insulin
B. Antidiuretic hormone
,C. Glucagon
D. Thyroxine
Answer: B
Rationale: Antidiuretic hormone (ADH) increases water permeability in the collecting ducts,
promoting water reabsorption.
4. Which hormone promotes sodium retention and potassium excretion?
A. Aldosterone
B. Insulin
C. Calcitonin
D. Melatonin
Answer: A
Rationale: Aldosterone promotes sodium and water retention while increasing potassium
excretion in the distal nephron.
5. The kidneys contribute to acid-base balance primarily by:
A. Excreting hydrogen ions and regulating bicarbonate
B. Producing oxygen
C. Removing carbon dioxide through the lungs
D. Producing gastric acid
Answer: A
Rationale: The kidneys regulate acid-base balance through hydrogen-ion excretion, bicarbonate
reabsorption, and generation of new bicarbonate.
6. Which substance is normally filtered by the glomerulus and commonly used to estimate
kidney filtration?
A. Creatinine
B. Albumin in large amounts
C. Red blood cells
D. Platelets
,Answer: A
Rationale: Serum creatinine is commonly used with other variables to estimate glomerular
filtration.
7. A decrease in glomerular filtration rate generally indicates:
A. Reduced kidney filtration capacity
B. Increased lung function
C. Improved renal function
D. Increased insulin secretion
Answer: A
Rationale: A reduced GFR indicates reduced filtration capacity and may occur with kidney
disease.
8. Which finding is most concerning for significant kidney dysfunction?
A. Persistent elevation in serum creatinine
B. Normal urine output
C. Stable electrolyte levels
D. Normal blood pressure
Answer: A
Rationale: Persistent creatinine elevation may indicate impaired kidney function and requires
clinical evaluation in context.
9. Which assessment is particularly important in a patient with advanced kidney disease?
A. Fluid status and blood pressure
B. Hair color
C. Hearing preference
D. Shoe size
Answer: A
Rationale: Fluid retention and hypertension are common complications of advanced kidney
disease.
, 10. Which electrolyte is especially important to monitor in advanced kidney disease?
A. Potassium
B. Nitrogen only
C. Oxygen
D. Chloride only
Answer: A
Rationale: Impaired renal potassium excretion can cause hyperkalemia, which may produce life-
threatening cardiac abnormalities.
Section 2: Chronic Kidney Disease
11. Chronic kidney disease is generally characterized by kidney abnormalities that persist for:
A. At least 3 months
B. 24 hours
C. 3 days
D. One week
Answer: A
Rationale: CKD is defined by abnormalities of kidney structure or function present for at least 3
months, with implications for health.
12. Which condition is a major cause of chronic kidney disease?
A. Diabetes mellitus
B. Seasonal allergies
C. Migraine
D. Appendicitis
Answer: A
Rationale: Diabetes is a leading cause of CKD.
13. Which other condition is a major risk factor for CKD progression?
2026–2027 | Comprehensive 100-Question
Practice Test with Answers & Rationales| Pdf
Access Already Graded A+.
Section 1: Renal Anatomy, Physiology & Assessment
1. What is the primary functional unit of the kidney?
A. Nephron
B. Alveolus
C. Hepatocyte
D. Neuron
Answer: A
Rationale: The nephron is the functional unit of the kidney and performs filtration,
reabsorption, and secretion.
2. Which structure is primarily responsible for initial filtration of blood in the nephron?
A. Loop of Henle
B. Glomerulus
C. Collecting duct
D. Distal tubule
Answer: B
Rationale: Blood is initially filtered through the glomerular capillaries into Bowman's capsule.
3. Which hormone increases water reabsorption in the kidney?
A. Insulin
B. Antidiuretic hormone
,C. Glucagon
D. Thyroxine
Answer: B
Rationale: Antidiuretic hormone (ADH) increases water permeability in the collecting ducts,
promoting water reabsorption.
4. Which hormone promotes sodium retention and potassium excretion?
A. Aldosterone
B. Insulin
C. Calcitonin
D. Melatonin
Answer: A
Rationale: Aldosterone promotes sodium and water retention while increasing potassium
excretion in the distal nephron.
5. The kidneys contribute to acid-base balance primarily by:
A. Excreting hydrogen ions and regulating bicarbonate
B. Producing oxygen
C. Removing carbon dioxide through the lungs
D. Producing gastric acid
Answer: A
Rationale: The kidneys regulate acid-base balance through hydrogen-ion excretion, bicarbonate
reabsorption, and generation of new bicarbonate.
6. Which substance is normally filtered by the glomerulus and commonly used to estimate
kidney filtration?
A. Creatinine
B. Albumin in large amounts
C. Red blood cells
D. Platelets
,Answer: A
Rationale: Serum creatinine is commonly used with other variables to estimate glomerular
filtration.
7. A decrease in glomerular filtration rate generally indicates:
A. Reduced kidney filtration capacity
B. Increased lung function
C. Improved renal function
D. Increased insulin secretion
Answer: A
Rationale: A reduced GFR indicates reduced filtration capacity and may occur with kidney
disease.
8. Which finding is most concerning for significant kidney dysfunction?
A. Persistent elevation in serum creatinine
B. Normal urine output
C. Stable electrolyte levels
D. Normal blood pressure
Answer: A
Rationale: Persistent creatinine elevation may indicate impaired kidney function and requires
clinical evaluation in context.
9. Which assessment is particularly important in a patient with advanced kidney disease?
A. Fluid status and blood pressure
B. Hair color
C. Hearing preference
D. Shoe size
Answer: A
Rationale: Fluid retention and hypertension are common complications of advanced kidney
disease.
, 10. Which electrolyte is especially important to monitor in advanced kidney disease?
A. Potassium
B. Nitrogen only
C. Oxygen
D. Chloride only
Answer: A
Rationale: Impaired renal potassium excretion can cause hyperkalemia, which may produce life-
threatening cardiac abnormalities.
Section 2: Chronic Kidney Disease
11. Chronic kidney disease is generally characterized by kidney abnormalities that persist for:
A. At least 3 months
B. 24 hours
C. 3 days
D. One week
Answer: A
Rationale: CKD is defined by abnormalities of kidney structure or function present for at least 3
months, with implications for health.
12. Which condition is a major cause of chronic kidney disease?
A. Diabetes mellitus
B. Seasonal allergies
C. Migraine
D. Appendicitis
Answer: A
Rationale: Diabetes is a leading cause of CKD.
13. Which other condition is a major risk factor for CKD progression?
